Teacher-related factors have been regarded as influential elements in molding the educational system; however, the role of some variables has been occasionally acknowledged in both mainstream education and English as a foreign language (EFL) educational settings and there exists a lack of comprehensive research exploring the link between work engagement, commitment to teaching, teacher effectiveness, and their Technological Pedagogical Content Knowledge (TPACK). As a result, the present study was set to test a structural model of work engagement, commitment to teaching, teacher effectiveness, and TPACK and specifically to examine the hypothesis that teacher effectiveness mediates the effects of work engagement, commitment to teaching, and TPACK. The participants were 157 Iranian TEFL teachers coming from various universities across Iran. Latent variable measurement models (work engagement, commitment to teaching, teacher effectiveness, and TPACK were validated by conducting Confirmatory Factor Analysis (CFA). Subsequently, Structural Equation Modeling (SEM) was employed to examine the structural model. The results revealed that commitment to teaching has no significant positive influence on TPACK. Work engagement was found to have a significant positive effect on TPACK, and work engagement was found to have significant positive effects on teacher effectiveness. In addition, teacher effectiveness was found to have a significant positive effect on TPACK. Finally, commitment to teaching has a significant positive influence on work engagement. Furthermore, commitment to teaching showed an indirect impact on TPACK through the mediation of work engagement. The findings have some implications for EFL stakeholders such as teachers, teacher education administrators, and policy makers.